Known hub-bearing assemblies have an axis of rotation and comprise:
a bearing outer ring which is radially delimited by a cylindrical outer surface that is coaxial with the axis of rotation and has a shaped groove formed through the cylindrical outer surface, and which is axially delimited by an annular outer surface transversal to the axis of rotation and adjacent to the cylindrical outer surface;
a bearing inner ring that defines with the outer ring an interspace, and is provided with a flange that is transversal to the axis of rotation; and
a sealing device, which is interposed between the outer ring and the inner ring to prevent the entry of any impurities into the hub-bearing assembly through the interspace, and comprises, in turn:
a first sealing shield which is integral with the outer ring and supports a sealing lip extending axially beyond the annular outer surface towards the flange; and
a second sealing shield which is integral with the inner ring and has a cylindrical wall placed around the cylindrical outer surface to define, at the position of the shaped groove, an inlet aperture of the interspace, and an annular wall placed behind the flange and in a position in front of the sealing lip.
In hub-bearing assemblies of the type described above, in order to increase the sealing capacity of the sealing device, that is to say in order to prevent the entry of contaminants and impurities into the interspace, the first sealing shield, which is essentially static because the outer ring is a static ring, is usually provided with one or more further sealing lips, each having a specific function, for example that of an oil seal or a dust seal. Such further sealing lips are commonly contacting lips, that is to say lips placed in sliding contact with the second shield or with the inner ring directly, but, although on the one hand the increase in the number of lips supported by the first shield improves the sealing capacity of the sealing device, on the other hand the presence of a plurality of contacting lips also increases the friction generated by the sealing device, possibly to the detriment of the performance of the corresponding hub-bearing assembly.